53 Pa. C.S. § 8706
After any county makes a countywide revision of assessment of real property at values based upon an established predetermined ratio as required by law or after any county changes its established predetermined ratio, each school district that has made an election under section 8703 (relating to adoption of referendum), which hereafter for the first time levies its real estate taxes on that revised assessment or valuation, shall for the first year reduce its tax rate, if necessary, for the purpose of having the percentage increase in taxes levied for that year against the real properties contained in the duplicate for the preceding year be less than or equal to the percentage increase in the Statewide average weekly wage for the preceding year notwithstanding the increased valuations of such properties under the revised assessment. For the purpose of determining the total amount of taxes to be levied for the first year, the amount to be levied on newly constructed buildings or structures or on increased valuations based on new improvements made to existing houses need not be considered. The tax rate shall be fixed for that year at a figure which will accomplish this purpose. The provisions of section 8704 (relating to public referendum requirements for increasing property taxes previously reduced) shall apply to increases in the tax rate above the limits provided in this section.
53 Pa.C.S. § 8706